

*{
  margin:0;
  padding: 0;
}
html,body{
  width: 100%;
  height: 100%;
  position: relative;
}
#app{
  width: 50%;
  height: 50%;
  display: flex;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
  background: url('../assets/image/bac.jpg') no-repeat;
  background-size: 100% 100%;
}
